Valve train assemblies of the above type are widely known. Their function resides in adapting the combustion process to the respective load requirements via the valve stroke height, and thus via the filling level of the cylinders of the internal combustion engine and, correspondingly, to achieve a largely efficient and thus also low-emission combustion. It is further known that, in certain load ranges; and particularly in the part-load range, a certain number of cylinders can be completely shut off, e.g., in order to run a four-cylinder internal combustion engine by operating only two cylinders. The focus here is also on efficiency and emission optimization of the combustion process. Numerous techniques are known with respect to cylinder shut-off. These include e.g., switchable key plungers, rocker arms with lost motion function, as well as push cams with zero stroke contour. These technical concepts have the problem that the respective activation and deactivation of the corresponding valves of the cylinder that is to be shut off must be performed when the corresponding valves are in the closed state, i.e., between two work cycles. The internal combustion engine will consequently experience a distinct load jump which must be dampened. The theoretical degrees of efficiency and advantages will again be partially lost in this manner.
DE 10 2006 033 559 A1 describes a mechanically controllable valve train comprising two valve stroke adjustment devices which can be driven independently from each other so that the valve stroke adjustment devices can also be used to shut off the cylinder. The provision of independently operable valve stroke adjustment devices will, however, increase expenditure for assembly and thereby costs.